Power tool and hammer drill

Abstract

A power tool can receive two different auxiliary handles in a replaceable manner. A power tool includes a tool body, a main handle, a cylindrical handle mount to which a first auxiliary handle or a second auxiliary handle is attachable and having a groove, the first auxiliary handle, and the second auxiliary handle. The first auxiliary handle includes an arc-shaped first band, a band holder that changes the diameter of the first band, and a first protrusion engageable with the groove. The second auxiliary handle includes an arc-shaped second band having a cutout in an axial direction, a fastener that changes the diameter of the second band, and a second protrusion engageable with the groove.

What is claimed is: 
     
         1 . A power tool, comprising:
 a tool body;   a main handle integral with the tool body;   a handle mount to which a first auxiliary handle or a second auxiliary handle is attachable, the handle mount being cylindrical and located in the tool body, the handle mount having a groove extending in an axial direction on an outer circumferential surface of the handle mount;   the first auxiliary handle including
 a first band being arc-shaped, 
 a band holder holding two ends of the first band to allow the first band to advance or recede to change a diameter of the first band, and 
 a first protrusion protruding radially inward from an inner circumferential surface of the band holder and engageable with the groove; and 
   the second auxiliary handle including
 a second band being arc-shaped, the second band having a cutout in an axial direction, 
 a fastener configured to adjust a circumferential width of the cutout to change a diameter of the second band, and 
 a second protrusion protruding radially inward from an inner circumferential surface of the second band and engageable with the groove. 
   
     
     
         2 . The power tool according to  claim 1 , wherein
 the tool body includes a portion ahead of the handle mount having a same diameter as or a smaller diameter than the handle mount.   
     
     
         3 . The power tool according to  claim 2 , wherein
 the handle mount includes
 a fastening surface to be in contact with an inner circumferential surface of the first band or the inner circumferential surface of the second band, and 
 a retainer at an end of the groove in the axial direction and protruding from the groove, 
   the retainer restricts movement of the first protrusion and the second protrusion in the axial direction, and   the retainer has a same radial height as or a smaller radial height than the fastening surface.   
     
     
         4 . The power tool according to  claim 2 , wherein
 the groove is longer in the axial direction than a width of the first protrusion in the axial direction and longer in the axial direction than a width of the second protrusion in the axial direction.   
     
     
         5 . The power tool according to  claim 2 , wherein
 an axial position of the first protrusion relative to the groove when the first auxiliary handle is attached to the handle mount coincides with an axial position of the second protrusion relative to the groove when the second auxiliary handle is attached to the handle mount.   
     
     
         6 . The power tool according to  claim 2 , wherein
 the first protrusion is located on an edge of the band holder in the axial direction, and   the second protrusion is located on an edge of the second band in the axial direction.   
     
     
         7 . The power tool according to  claim 1 , wherein
 the handle mount includes
 a fastening surface to be in contact with an inner circumferential surface of the first band or the inner circumferential surface of the second band, and 
 a retainer at an end of the groove in the axial direction and protruding from the groove, 
   the retainer restricts movement of the first protrusion and the second protrusion in the axial direction, and   the retainer has a same radial height as or a smaller radial height than the fastening surface.   
     
     
         8 . The power tool according to  claim 7 , wherein
 the groove is longer in the axial direction than a width of the first protrusion in the axial direction and longer in the axial direction than a width of the second protrusion in the axial direction.   
     
     
         9 . The power tool according to  claim 7 , wherein
 an axial position of the first protrusion relative to the groove when the first auxiliary handle is attached to the handle mount coincides with an axial position of the second protrusion relative to the groove when the second auxiliary handle is attached to the handle mount.   
     
     
         10 . The power tool according to  claim 7 , wherein
 the first protrusion is located on an edge of the band holder in the axial direction, and   the second protrusion is located on an edge of the second band in the axial direction.   
     
     
         11 . The power tool according to  claim 1 , wherein
 the groove is longer in the axial direction than a width of the first protrusion in the axial direction and longer in the axial direction than a width of the second protrusion in the axial direction.   
     
     
         12 . The power tool according to  claim 11 , wherein
 an axial position of the first protrusion relative to the groove when the first auxiliary handle is attached to the handle mount coincides with an axial position of the second protrusion relative to the groove when the second auxiliary handle is attached to the handle mount.   
     
     
         13 . The power tool according to  claim 1 , wherein
 an axial position of the first protrusion relative to the groove when the first auxiliary handle is attached to the handle mount coincides with an axial position of the second protrusion relative to the groove when the second auxiliary handle is attached to the handle mount.   
     
     
         14 . The power tool according to  claim 1 , wherein
 the first protrusion is located on an edge of the band holder in the axial direction, and   the second protrusion is located on an edge of the second band in the axial direction.   
     
     
         15 . The power tool according to  claim 1 , wherein
 the handle mount has a plurality of the grooves in a circumferential direction.   
     
     
         16 . The power tool according to  claim 15 , wherein
 two of the plurality of grooves face each other in a radial direction of the handle mount.   
     
     
         17 . The power tool according to  claim 15 , wherein
 the plurality of grooves are four or more grooves located at equal intervals in the circumferential direction of the handle mount.   
     
     
         18 . A hammer drill, comprising:
 the power tool according to  claim 1 ; and   a tip tool attachable to the power tool.   
     
     
         19 . The power tool according to  claim 1 , wherein
 the first band is formed from an iron, and   the second band is formed from a resin.   
     
     
         20 . The power tool according to  claim 19 , wherein
 the fastener adjusts the circumferential width of the cutout by elastically deforming the second band.